Systems Research and Architecture Group (SRA)

Fachgebiet System- und Rechnerarchitektur

Our Research and Teaching activities are centered around the architecture of computing systems: From hardware over system software up to languages and compilers with a focus on constructive methods for the design and development of adaptable and versatile system software. The group is led by Prof. Daniel Lohmann.

Cherrapunjee Rain Forests" ( CC BY-SA 2.0) by  ashwin kumar


Those machines that are closest to our everyday life are special-purpose systems embedded into the physical world. Due to this embedding, we know a lot about the surroundings of a system. We exploit this knowledge in the design of hardware and system software.


The requirements for every system are special. However, we often favor unspecific general-purpose components over special-purpose solutions. With the techniques of automatic tailoring, we can achieve specialized systems at moderate development costs.


During the architectural design, the required functionalities are often well understood. Nonfunctional aspects are decisive for choosing a system for a given task. Especially for embedded systems, we can optimize various aspects towards the given application scenario.

News and Trivia

2019-02-15 New Colleague at SRA
Tobias Landsberg joins the SRA team as Doctoral Researcher. He will strengthen our research team and, in the upcoming semester, he will manage our Bachelor's seminar (Proseminar Parallelverarbeitung) and assist in our Master's project (Projekt SRA). Welcome, Tobias!
2018-12-20 Malte Bargholz erhält Auszeichnung für Bachelorzeugnis

Der Student Malte Bargholz wurde im Rahmen des Tags der Fakultät für seine herausragenden Leistungen in seiner Bachelorprüfung geehrt. Seine herausragenden Leistungen stellte er, unter anderem, in seiner Bachelorarbeit InterSloth: Globales Hardware-gesteuertes Scheduling in einem Multikern-Echtzeitbetriebssystem auf RISC-V beim SRA unter Beweis und konnte seine Ergebnisse beim Herbsttreffen der Fachgruppe Betriebssysteme vorstellen.

2018-12-14 Semi-Extended Tasks at RTSS 2018
Christian Dietrich presents the paper Semi-Extended Tasks: Efficient Stack Sharing Among Blocking Threads at the IEEE Real-Time Systems Symposium in Nashville, TE, USA (RTSS `18). In the paper we adress the problem of worst-case stack consumption (WCSC) in real-time systems that support preemption and blocking of threads. We refine the stack-sharing granularity from the thread to function level and provide an efficient intra-thread stack-switch mechanism as well as an ILP-based analysis approach to realize tight WCSC boundaries.
2018-11-26 Inaugural Lecture

Prof. Dr.-Ing. habil. Daniel Lohmann gave his inaugural lecture at the Faculty of Electrical Engineering and Computer Science. In his presentation "Klein und sicher – Automatisch anpassbare Systemsoftware für eingebettete Spezialzweckanwendungen", Prof. Lohmann provided an entertaining introduction into our research activities and the case for highly tailorable system software.

2018-10-18 Herbsttreffen der Fachgruppe Betriebssysteme in Coburg

Studenten und Mitarbeiter des SRA nehmen am Herbstreffen der Fachgruppe Betriebssysteme in Coburg teil. Das SRA ist mit zwei Vorträgen vertreten. Malte Bargholz spricht über „InterSloth: Hardwaregestützte, globale und prioritätsgesteuerte Echtzeiteinplanung“ und Christian Dietrich präsentiert seine Arbeit über „Semi-Extended Tasks: Geteilter Stack für selbstblockierende Fäden“.

2018-10-01 New Colleague at SRA
Stefan Naumann joins the SRA team as Doctoral Researcher. He will strengthen our research team and, in this semester, he will manage our Master's seminar on Coprocessors and their Management in Operating Systems. Welcome, Stefan!
2018-07-03 Best Paper: Levels of Specialization in Real-Time Operating Systems at OSPERT '18

Björn Fiedler presents our paper Levels of Specialization in Real-Time Operating Systems was at the 14th Workshop on Operating System Platforms for Embedded Real-Time Applications (OSPERT '18), in Barcelona. In the paper we describe a taxonomy for the specialization of system software towards a specific application and provide showcases of the achievable benefits. We got an Best Paper Award for this work.

2018-06-29 Visit by Wolfgang Schröder-Preikschat, FAU Erlangen-Nürnberg
Wolfgang Schröder-Preikschat is visiting our group and will present his work in the computer science colloquium.

Predictability Issues in Operating Systems, 15:00, L3S multimedia room, Appelstr. 9, 15th floor

Predictability is always subject to the underlying assumptions being made. For real-time systems, time response of processes in relation to the strictness of deadlines is of particular importance. With an additional focus on embedded systems, space and energy requirements become relevant as well and need to be considered in combination. As far as software is concerned, structure and organisation of the programs to be executed determines whether or not predictable processes will take place in a given computing system. Design for predictability is an overarching aspect that crosscuts the whole computing system and particularly addresses operating systems.

This talk is about structuring principles of non-sequential programs - in the shape of but not limited to operating systems - to abet predetermination of quality attributes of non-sequential (real-time) processes, it is not about analytical methods to effectively predetermine these attributes. Issues in operating systems as to space, timing, and energy requirement are touched. Emphasis thereby is on coordination of cooperation and competition between processes, namely synchronisation. It is shown how measures of process synchronisation against the background of many-core processors cater to these issues.
2018-06-27 Cross-Layer Fault Space Pruning at DAC 2018
Our paper Cross-Layer Fault-Space Pruning for Hardware-Assisted Fault Injection is presented by Christian Dietrich at the 55th Design Automation Conference in San Francisco. The paper describes a method to calculate fault-masking terms that are used to prune the fault space of a flip-flop level fault injection dynamically. Thereby, we can shrink the fault space by up to 20 percent.
2018-04-01 Verabschiedung von Prof. Dr.-Ing. Christian Müller-Schloer
Nach einer langen und erfolgreichen akademischen Karriere verabschiedet sich der bisherige Leiter des Fachgebietes System- und Rechnerarchitektur, Herr Prof. Dr.-Ing. Christian Müller-Schloer, zum 1. April 2018 in den wohlverdienten Ruhestand. Nach Studium und Promotion an der Technischen Universität München arbeitete Prof. Müller-Schloer bei den Siemens Corporate Research Labartories. Im Jahr 1991 erhielt er den Ruf an die Leibniz Universität Hannover und gründete den heutigen Fachbereich System- und Rechnerarchitektur, der zunächst unter dem Namen "Institut für Rechnerstrukturen und Betriebssysteme" firmierte und die Entstehung und Entwicklung der Informatik an der Leibniz Universität Hannover maßgeblich prägte. Neben seinem hohen Einsatz für die Informatik in Hannover über viele Jahre hinweg, begründete und prägte Prof. Christian Müller-Schloer das Forschungsgebiet des Organic Computing. Der Fachbereich System- und Rechnerarchitektur verabschiedet sich von seinem langjährigen Leiter und bedankt sich für viele Jahre interessanter Diskussionen, gemeinsam errungenener Erkenntnisse und schöner Erlebnisse.

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